Phosphoroamidates

ABSTRACT

Compounds of the formulas ##STR1## WHEREIN: X represents oxygen or sulfur; 
     Z represents the residue of a hydroxyl-containing moiety; 
     R 1  and R 2  in formula (1) may be the same or different and individually represent alkyl, cycloalkyl or aryl and, together with the common nitrogen atom, represent a 5 or 6 member ring containing oxygen, sulfur or nitrogen or combination thereof; 
     Nr 1  r 2  in formula (2) represents a 5 or 6 member ring containing oxygen, sulfur or nitrogen or combination thereof; 
     n represents an integer having a value of 2 or greater and is equal to the number of hydroxyl groups on the orginal hydroxyl-containing moiety, the residue of which is now represented by Z. 
     are prepared by reacting a phosphorohalidate with an amine in an organic solvent containing aqueous alkali metal or ammonium hydroxide. 
     The compounds are useful as flame retardants for natural and synthetic materials.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation-in-part of copending application Ser.No. 599,569, filed July 28, 1975, now abandoned, which was a divisionalof application Ser. No. 459,257, filed Apr. 8, 1974, now abandoned whichwas a continuation-in-part of application Ser. No. 276,810 filed July31, 1972, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to (a) a novel process for preparingphosphoroamidates, (b) novel flame retardant polymer compositionscontaining certain known phosphoroamidates, (c) novel phosphoroamidatesand (d) novel flame retardant polymer compositions containing novelphosphoroamidates.

(a) Process

In the past, one method of preparing phosphoroamidates has been carriedout by reacting a corresponding phosphorohalidate with an excess of anappropriate amine in an organic diluent. This method is disadvantageoussince salts are formed during the reaction which precipite from theorganic solution and must be separated and since the only means ofscavenging hydrogen chloride formed during the reaction is by the use ofexcess amine which is quite expensive.

It was also known, of course, that aqueous caustic is a hydrogenchloride scavenger but that knowledge was not believed adaptable to thepreparation of phosphoroamidates since it appeared obvious that aqueouscaustic would hydrolyze the intermediate phosphorohalidate to phosphoricacid.

(b) Known Phosphoroamidates

The following patents disclose phosphoroamidates prepared from simplealiphatic and aromatic alcohols, phosphorus oxyhalide or thiohalide andan amine:

U.s. pat. No. 2,385,713 U.S. Pat. No. 3,531,550

U.s. pat. No. 2,912,451 U.S. Pat. No. 3,584,085

U.s. pat. No. 3,328,494

U.S. Pat. No. 2,385,713 discloses compounds of the formula(Phenyl-O)_(m) P(O)(NX₂)_(n) wherein X ═ H or hydrocarbon and m + n = 3.The compounds are esters of amidophosphoric acids with substitutedphenols and have utility as germicides and bactericides. With regard tothe present invention, the patent indicates no distinction between theuse of primary and secondary amines, contains an enabling disclosuredirected only to "diamidophosphates" and, while disclosing certaincompounds within the scope of formula (1) of this invention, does notteach the use of phosphorodiamidates as flame retardants.

U.S. Pat. No. 2,912,451 discloses acyclic tetramethylphosphorodiamidateshaving utility as weed killers. With regard to the present invention,the patent discloses amidation only with dimethylamine, makes onlytetramethylphosphoroamidates and does not teach the use ofphosphordiamidates as flame retardants, although disclosing certaincompounds falling within the scope of formula (1) of this invention.

U.S. Pat. No. 3,328,494 discloses O-(2-naphthyl)phosphorothionates,which may be mono- or diamido substituted, having utility as herbicides.With regard to the present invention, the patent does not disclose aprocess suing an alkali metal hydroxide and, while disclosing certainN,N'-di-lower alkylamido compounds falling within the scope of formula(1) of this invention, does not distinguish between those compounds thethe disclosed diamido compounds and does not teach the use ofphosphorodiamidates as flame retardants.

U.S. Pat. No. 3,531,550 discloses certain phosphorus ester mono- anddiamides having utility as functional fluids. With regard to the presentinvention, the patent does not use a process involving alkali metalhydroxide and, while disclosing certain compounds within the scope offormula (1) of this invention, does not teach the use ofphosphorodiamidates as flame retardants.

U.S. Pat. No. 3,584,085 discloses the use of certainphosphoromonoamidates as flame retardants for polyurethanes. With regardto the present invention, the patent does not disclose the use of analkali metal hydroxide and prepares hydroxyalkyl, halophenyl, hydrogenand alkyl-substituted amides which are not within the scope of formula(1) of this invention.

(c) Novel Phosphoroamidates

The following patents disclose phosphoroamidates which are relevant tothe compounds of formula (2) of this invention:

U.s. pat. No. 3,254,050

U.s. pat. No. 3,335,129

W. german Pat. No. 2,104,569

U.S. Pat. No. 3,254,050 discloses certain bisphenol biphosphites asflame retardants for various resin systems. With regard to the presentinvention, the patent does not prepare amidates from bisphenol compoundsas defined in formula (2) of the present invention.

U.S. Pat. No. 3,335,129 discloses certain phosphoromono- and diamidateshaving utility as flame retardants for various resin systems. Withregard to the present invention, the patented compounds must containfree hydroxyl groups to provide a reactive site so the compounds may bereacted with the resin systems which they are intended to flame retard.In contrast thereto, the compounds of formula (2) of this inventioncontain no free hydroxyl groups.

W. German Pat. No. 2,104,569 discloses certain haloalkylamides as flameretardants for polyurethanes. The compounds of formulas (II) and (III)of the patent are distinguished from the compounds of formula (2) ofthis invention since the compounds of this invention are nothaloalkylamide-substituted phosphorus compounds.

(d) Novel Polymer Compositions

The following patents disclose phosphoramidate/resin compositions whichare relevant to the polymer compositions containing compounds as definedin formula (2):

U.s. pat. No. 3,256,249

W. german Pat. No. 2,104,569

U.S. Pat. No. 3,256,249 is relevant to the polymer compositions of thisinvention which contain compounds of formula (2). The patent discloseshydroxylated phosphoromono- and diamides as flame retardants in variousresin systems. In contrast thereto, the polymer compositions of thisinvention do not contain hydroxylated phosphoroamidate flame retardants.

W. German Pat. No. 2,104,569 discloses haloalkylamide-substitutedphosphorus compounds as flame retardants for polyurethanes. With regardto the present invention, the compounds of formulas (II) and (III) ofthe patent are haloalkylamide-substituted compounds while those offormula (2) of this invention contain no haloalkylamide substituents.

SUMMARY OF THE INVENTION

It has been found that certain phosphoroamidates are useful as flameretardant additives and that such compounds may be prepared by thereaction of a phosphorus halidate with an amine in an organic diluentcontaining an aqueous solution of an alkali metal or ammonium hydroxide.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The compounds of this invention are prepared by reaction of ahydroxyl-containing moiety with a phosphorus oxyhalide or phosphorusthiohalide to afford a phosphorohalidate which is then reacted with asecondary amine in an organic diluent containing an aqueous solution ofan alkali metal hydroxide.

The compound of this invention are represented by the formulas ##STR2##wherein X represents oxygen or sulfur;

Z-represents the residue of a hydroxyl-containing moiety;

R₁ and R₂ in formula (1) individually represent alkyl, cycloalkyl oraryl, and may be the same or different and, together with their commonnitrogen atom represent a 5 or 6 member ring containing oxygen, sulfuror nitrogen or combination thereof;

Nr₁ r₂ in formula (2) represents a 5 or 6-member ring containing oxygen,sulfur or nitrogen or combination thereof;

n represents an integer having a value of 2 or greater and is equal tothe number of hydroxyl groups on the original hydroxyl-containingmoiety, the residue of which is herein-represented by Z.

It is understood that the acid and alkaline and ammonium salts ofcompounds of formulas (1) and (2) are within the scope of the invention,i.e., hydrochlorides, sulfates, toluenesulfonates and the like.Accordingly, reference hereinafter to a group of compounds or to aspecific compound within a group is intended to include the acid andalkaline and ammonium slat thereof.

Generalized reaction schemes for preparing the compounds of formulas (1)and (2) of the invention are as follows: ##STR3## wherein X, Z, R₁, R₂and n are identified above.

Hydroxyl-containing compounds which are reacted with a phosphorusoxyhalide or thiohalide to obtain phosphorohalidates orthiophosphorohalides are represented by the formulas

    ZOH and

    (4) Z--OH).sub.n

where n represents an integer having a value of 2 or greater.

The particular hydroxyl-containing compound used is not critical,insofar as the preparation of the phosphorohalidate intermediate isconcerned, since any hydroxyl-containing material which will react witha phosphorus oxyhalide or phosphorus thiohalide may be utilized.Additionally, the hydroxyl-containing compound may be the reactionproduct of a hydroxyl-containing compound and an alkylene oxide.

Illustrative examples of hydroxyl-containing compounds represented byZOH and Z--OH)_(n) include substituted and nonsubstituted hydrocarbonchains which may be aliphatic or branched-chain, saturated orunsaturated, aromatic or mixed aliphatic/aromatic or cyclic incharacter, e.g., aliphatic and aromatic alcohols such as mono- andpoly-hydroxy aliphatic or aromatic alcohols and phenols, carbohydratesand hydroxyl-containing higher polymers whether natural or synthetic inorigin.

Exemplary aliphatic alcohols which are used include methanol, ethanol,propanol, isopropanol, butanol, isobutanol, nonanol, isononanol,decanol, octadecanol, allyl alcohol, phytol, ethylene glycol, farnesol,propylene glycol, trimethylene glycol, glycerol, β-chloroethanol, glycolmethyl ether, glycol ethyl ether, citronellol, ethylene chlorohydrin,diethylene glycol, carbitol, 1,2-butanediol, 2,3-butanediol,pentamethylene glycol, geraniol, xanthyl alcohol, naphthyl alcohol,erythritol, arabitol, sorbitol, mixtures of C₇, C₉ and C₁₁ alcohols, andmixtures of C₆, C₈, C₁₀ and C₁₂ alcohols.

Cyclic alcohols include cyclopentanol, cyclohexanol,pentahydroxycyclohexane, terpineol, hexahydroxycyclohexane,cyclopropylcarbinol, borneol, cyclohexanediol, cyclohexanedimethanol.

Aromatic alcohols include trimellitic alcohol, benzyl alcohol,β-phenylethanol, β-phenoxyethanol, α-phenylethanol, phenylallyl alcohol,diphenylcarbinol, triphenylcarbinol, salicyl alcohol

Phenols include phenol, bis(alkylidene)phenols such as4,4'-isopropylidene diphenol, allylphenol, nitrosophenol, cresol, methylphenol, ethyl phenol, thymol, carvacrol, p-α-propenylphenol, resorcinol,aminophenol, catechol, quinol, adrenaline, hexylresorcinol,hydroquinone, trihydroxybenzene, pyrogallol.

Carbohydrates include the aldotetroses, the aldopentoses, e.g., xylose,ribose, the aldohexoses, e.g., glucose, the disaccharides, e.g.,sucrose, lactose, maltose, the trisaccharides, e.g., raffinose,sorbitol, rahmnose, fructose, glycosides, cellobiose, polysaccharides,e.g., starch, cellulose.

Higher polymer materials include the polyalkylene glycols, polyvinylalcohol, hydrolyzed vinyl acetate/vinyl alcohol copolymers, phenolicresins.

Other hydroxyl-containing materials, such as dihydroxyacetone, glycerylmonostearate, glyceraldehyde, cellosolve acetate and hydroxyacetophenonemay be used.

Primary or secondary alcohols or phenols are the preferredhydroxyl-containing material. Tertiary alcohols are unsuitable sincereaction thereof with a phosphoryl halide affords an alkyl halide ratherthan a phosphorohalidate.

A preferred class of hydroxyl-containing compounds are represented byphenol, o, m, p-cresol, o-ethylphenol, o, m, p-isopropylphenol,p-tert-butylphenol, p-tert-amylphenol, nonylphenol, xylenol, o, m,p-chlorophenol, p-bromophenol, p-iodophenol, dichlorophenol,trichlorophenol, pentachlorophenol, p-cumylphenol, o-cyclohexylphenol,naphthol, methoxyphenol, ethoxyphenol, phenoxyphenol, p-nitrophenol,trifluoromethylphenol, allylphenol, benzylphenol, vanillin,4-chloro-3,5-dimethylphenol, 4-chloro-1-naphthol,2-chloro-4-nitrophenol, cyanophenol, di-tert-butylphenol,dimethoxyphenol, methylsalicylate, fluorophenol. Especially preferred ofthis group are phenol, cresol, cumylphenol, nonylphenol, chlorophenol,xylenol, tert-butylphenol, phenylphenol, isopropylphenol and mixturesthereof.

Another preferred class of hydroxyl-containing materials includescyclohexanedimethanol, isopropylidene diphenol, hydroquinone, catecholand resorcinol.

It is essential that the alcohol, i.e. the original hydroxyl-containingmoiety, contain no free-hydroxyl groups after the reaction with aphosphorus oxyhalide or phosphorus thiohalide, since a free-hydroxylgroup would react with any remaining P-chlorine linkages, thus leavingno reactive site for the subsequent amidation.

Alkyl radicals represented by R₁ and R₂ in formulas (1) and (2) includemethyl, ethyl, propyl, isopropyl, butyl, amyl, hexyl, heptyl, octyl,nonyl, decyl, octadecyl, benzyl, β-phenylethyl.

Aryl radicals represented by R₁ and R₂ in formulas (1) and (2) includephenyl, alkyl-substituted phenyl, e.g., methyl phenyl, diethyl phenyl,naphthyl, chlorophenyl.

Cycloalkyl radicals represented by R₁ and R₂ in formulas (1) and (2)include cyclohexyl, cyclopentyl, cyclobutyl.

Five and six-member rings, containing oxygen, sulfur, nitrogen andcombinations thereof, represented by R₁ and R₂, together, in formulas(1) and (2) include thiazole, pyridine, pyrrole, isoxazole, oxazole,pyrazole, imidazole, thiazoline, thiazolidine, thiopyran, collidine,hexahydropyridine, piperidine, morpholine, condensed ring systems suchas benzopyrrole, quinoline and carbazole.

The phosphorus halides and phosphorus thiohalides which are utilizedherein include, for example, phosphorus oxytrichloride, phosphorusoxytribromide, phosphorus oxytrifluoride, phosphorus oxydichloridebromide, phosphorus oxydibromide chloride, phosphorus oxydifluoridechloride and the corresponding thiophosphorus analogs.

The phosphorohalidates, which are reacted with a secondary amine toobtain the compounds of this invention, are prepared as described aboveand by methods known in the art, are represented by the formulas##STR4## wherein hal represents halogen, e.g., chlorine, fluorine,bromine or iodine and Z, X and n are as defined in formulas (1) and (2).

Illustrative phosphorohalidates utilized to prepare the novel compoundsof this invention include phenyl phosphorodichloridate, chlorophenylphosphorodichloridate, chlorophenyl phosphorodibromidate, nitrophenylphosphorodichloridate, cresyl phosphorodichloridate, methoxyphenylphosphorodibromidate, nonylphenyl phosphorodichloridate, cumylphenylphosphorodichloridate, biphenyl phosphorodichloridate, naphthylphosphorodichloridate, isopropylphenyl phosphorodichloridate,tert-butylphenyl phosphorodichloridate, isodecylphenylphosphorodichloridate, isodecyl phosphorodichloridate, isopropylidenedi-p-phenylene bisphosphorodichloridate, isopropylidene di-p-phenylphosphorodichloridate, cyclohexylenedimethylene bisphosphorodichloridate, dicresyl phosphorodichloridate, dixylylphosphorodichloridate, n-propylene bis phosphorodichloridate, n-butylenebis phosphorodichloridate and the polyphosphorodichloridates ofcarbohydrates and other hydroxyl-containing polymeric materials.

The secondary amines utilized in accordance with this invention arecharacterized by the formula ##STR5## wherein R₁ and R₂ individually ortogether are as defined in formulas (1) and (2). Preferably, one of R₁and R₂ is a methyl group.

Illustrative amines include the alkylamines, e.g., dimethylamine, methylethyl amine, methyl butyl amine, dibutyl amine, dioctyl amine,di-n-hexylamine, didecyl amine, di-n-octadecylamine, dibenzylamine,di-β-phenylethylamine; cycloalkyl amines, e.g., butylcyclohexyl amine,dicyclopentyl amine; and similar compounds.

The reaction of a slight excess of a polyfunctional amine with aphosphorohalidate affords polymeric compounds of this invention havingthe formula ##STR6## wherein R represents an alkylene group of 1 to 50carbon atoms or an arylene group;

R₃ and R₄ individually represent an alkyl group of 1 to 10 carbon atomsor, together with the nitrogen atom, a 5 or 6 member heterocyclic ring;

X represents oxygen or sulfur;

Z represents the residue of a hydroxyl-containing moiety; and

n represents an integer from 1 to 40.

Polyfunctional amines which are used to prepare the compounds of formula(8) are represented by the formula ##STR7## wherein R, R₃ and R₄ aredefined in formula (8).

Illustrative amines corresponding to formula (9) include those compoundswhere R preferably represents an alkylene group of 1 to 10 carbon atomsand one of R₃ and R₄ is preferably methyl, e.g.,bis(methylamino)methane, bis(methylamino)ethane,bis(methylamino)propane, bis(methylamino)butane, bis(ethylamino) octane,bis(methylamino)benzene and the like.

Preferred groups of compounds in accordance with this invention includecompounds of the formulas ##STR8## wherein R₁ and R₂ individuallyrepresent an alkyl group of 1 to 10 carbon atoms or an aryl group or analkyl-aryl group;

R₁ and R₂, each together with its attached nitrogen atom, represent a 5or 6 member heterocyclic ring which may additionally contain oxygen,sulfur or nitrogen;

R₅ represents hydrogen, an alkyl group of 1 to 20 carbon atoms, an arylgroup, an alkylaryl group or halogen;

R₆ and R₇ individually represent hydrogen, an alkyl group of 1 to 10carbon atoms, an aryl group or an alkylaryl group;

R₈ represents hydrogen or an alkyl, cycloalkyl, alkaryl, aryl or aralkylgroup;

X represents oxygen or sulfur;

A represents a methylene or phenylene group;

B represents hydrogen or ##STR9## Q represents an alkyl group of 1 to 20carbon atoms, an aryl group, an alkylaryl group, a carbonyl or sulfonylgroup, an aliphatic or aromatic ester group or ##STR10## n₁ representsan integer having a value of 0, or 1 to 6 when

A ═ methylene or 1 to 2 when A ═ phenylene; and

n₂ represents an integer having a value of 1 to 50.

Compounds of formula (10) are prepared, for example, by reaction ofisopropylidene diphenol (e.g., bisphenol A) or phenylisopropylphenolwith phosphorus oxychloride or phosphorus thiochloride and subsequentreaction of the phosphorodichloridate intermediate with a secondaryamine described above.

Exemplary compounds represented by formula (10), where B ═ hydrogen,include:C₆ H₅ C(CH₃)₂ C₆ H₄ OP(O)[N(CH₃)₂]₂C₆ H₅ CH₂ C₆ H₄ OP(S)[N(CH₃)₂]₂ ##STR11##C₆ H₅ CH₂ C₆ H₃ (CH₃)OP(O)[N(C₃H₇)₂ ]₂ ##STR12## ##STR13##C₆H₅ C(C₃ H₇)₂ C₆ H₃ (C₆H₅)OP(O)[N(C₆ H₅)₂ ]₂C₆ H₅ C(C₁₂ H₂₅)₂ C₆ H₃(C₅H.sub. 11)OP(O)[N(C₁₀ H₂₁)₂ ]₂ ##STR14## ##STR15##Exemplary compoundsof formula (10), where B = ##STR16## ##STR17## ##STR18## ##STR19####STR20##Compounds of formula ( 11) are prepared, for example, byreaction ofbenzyl alcohol, cyclohexanemethanol, phenylphenol,cyclohexanol,hydroxymethylphenol, hydroxycyclohexanemethanol,bis-hydroxy diphenyl,cyclohexanediol, cyclohexanedimethanol,bis(hydroxymethyl)benzene orother appropriate compounds with aphosphorus oxyhalide or phosphorus

Exemplary compounds represented by formula (11), where B ═ hydrogen,include: ##STR21##

Exemplary compounds of formula (11), where ##STR22## include: [(H₃ C)₂N]₂ (O)POH₂ CC₆ H₁₀ CH₂ OP(O)[N(CH₃)₂ ]₂ ##STR23## [(H₃ C)₂ N]₂ (O(POC₆H₁₀ OP(O)[N(CH₃)₂ ]₂

Compounds of formula (12) are prepared by reaction of a polyol (e.g.,the reaction product of an alkylene oxide and a glycol) with aphosphorus oxyhalide or thiohalide and an amine ad described above.

Exemplary compounds represented by formula (12) include: ##STR24##

The proportion of phosphorodihalidate and amine which are reacted willvary, depending upon reaction conditions. Generally, however, sufficientamine is added to completely convert the phosphorodihalidate to thecorresponding phosphorodiamidate, e.g., two moles or more of amine permole of phosphorodihalidate.

The reaction of the phosphorodihalidate and amine may be conducted in anaqueous medium but is preferably conducted in an organic diluentcontaining an aqueous solution of an alkali metal or ammonium hydroxideso that the alkali metal hydroxide will scavenge liberated hydrogenchloride. Organic diluents which may be used include any of theconventional organic diluents such as chlorobenzene, tetrahydrofuran andthe like.

The temperature of the phosphorohalidate/amine reaction may vary fromabout 0° to about 100° C., although the preferred temperature range isfrom about 10° to about 60° C. Higher temperatures may be used butreduce yield.

The following examples illustrate specific embodiments of thepreparation of certain compounds of the invention and are not to beconstrued as limiting the scope thereof.

EXAMPLE 1

In a one-liter flask, fitted with mechanical stirrer, condenser andthermometer, are placed 228 g. (1.0 mole) of bisphenol A, 460 g. (3.0moles) of phosphorus oxychloride, and 3.0 g. of pyridine. The solutionis heated to reflux. At about 90° C., hydrogen chloride starts to evolveand is passed to a water scrubber. After 21/2 hours, the temperature ofthe reaction mass stabilizes at 135° C. and no further hydrogen chlorideis liberated. The excess phosphorus oxychloride is removed by vacuumdistillating the mass at 100° C. to 40 mm of Hg. There is recovered 144g. of phosphorus oxychloride. The residue is 459 g. of product (99% oftheory) and is isopropylidene di-p-phenylene bis-phosphorodichloridate:##STR25##

EXAMPLE 2

In a two liter flask, fitted with mechanical stirrer, dropping funnel,condenser and thermometer, are placed 800 g. of 25 percent dimethylamine solution and 340 g. of 50 percent sodium hydroxide solution. Themixture is cooled during the addition to 15° C. by means of an ice waterbath. By means of a dropping funnel, 461 g. (1.0 mole) of isopropylidenedi-p-phenylene bis-phosphorodichloridate (prepared as described inExample 1) in 200 ml. of monochlorobenzene is added dropwise over a twohour period. The temperature is maintained at 15°±2° C. After theaddition is complete, the mixture is stirred for one-half hour and thenheated to 60° C. over a half hour period. Layers are separated and theorganic layer is washed at 70° C. with 700 ml. of water for 20 minutes.The organic layer is then vacuum stripped to 135° C./40 mm. Hg and thensteam sparged at 135° C./40 mm. Hg. for 30 minutes. The product isdehydrated and filtered. There is obtained 465 g. (94% of theory) of theproduct, which is isopropylidene di-p-phenylenebis(tetramethylphosphorodiamidate): ##STR26##

EXAMPLE 3

Morpholine (400 gms.) is dissolved in 600 ml. water, cooled to 15° C. ina 2 liter, 3-necked flask cooled by a water bath. A fifty percentsolution of sodium hydroxide (340 gms.) is added and then, using adropping funnel, isopropylidene di-p-phenylene bis phosphorodichloridate(461 gms.) in monochlorobenzene (200 ml.) is added over a two-hourperiod maintaining the temperature at 15°±2° C. After addition, themixture is stirred at 15° C. for one-half hour and then heated to 60° C.over one-half hour. The mixture is placed in a two liter separatoryfunnel and the salt layer is discarded. The organic layer is washed with700 ml. water at 60°-65° C. for 2 minutes. The water layer is discardedand the organic layer is washed with 10 gms. sodium hydroxide in 700 ml.water at 70°-75° C. for 20 minutes, stripped and steamed at 135° C./40mm. Hg. for one-half hour. There is obtained a 90 percent yield ofproduct, isopropylidene di-p-phenylenebis(dimorpholinophosphorodiamidate): ##STR27##

Substituting other amines in place of morpholine in the above procedureaffords the following compounds:

    __________________________________________________________________________    Amine   Compound                                                              __________________________________________________________________________     ##STR28##                                                                             ##STR29##                                                             ##STR30##                                                                             ##STR31##                                                             ##STR32##                                                                             ##STR33##                                                        

In a one liter flask, fitted with reflux condenser thermometer andmechanical stirrer, are placed cumylphenol (424 gms.), phosphorusoxychloride (460 gms.) and pyridine (3.0 gms.). The mixture is heated toreflux which starts at 95° C. with evolution of hydrogen chloride. Overa period of three hours the temperature slowly rises to 145° C. and ismaintained at that temperature for an additional one-half hour. Themixture is vacuum stripped to recover phosphorus oxychloride. Theresidue is diluted with monochlorobenzene (200 ml.) and added to apreviously prepared solution of dimethylamine (800 gms. -- 25 percent inwater) and sodium hydroxide (350 gms. -- 50 percent in water). Themixture is cooled to 15°-20° C. during the addition over one andone-half hours. The mixture is then heated to 70° C. and the layers areseparated. The organic layer is washed with water at 70° C., dehydrated,steamed and filtered.

The product (628 gms. -- 91 percent yield) is cumylphenyltetramethylphosphorodiamidate: ##STR34##

EXAMPLE 5

In a one liter flask, fitted with reflux condenser, mechanical stirrerand thermometer, are placed nonylphenol (440 gms.), phosphorusoxychloride (460 gms.) and pyridine (3.0 gms.). The procedure of Example4 is then followed and the mixture residue is diluted withmonochlorobenzene (200 ml.) and added to a morpholine (400 gms.)/caustic(350 gms.) solution. A ninety percent yield (787 gms.) of nonylphenyldimorpholinophosphorodiamidate is obtained: ##STR35##

Repeating the above procedure with substitution of 800 gms.dimethylamine of 25 percent solution for 400 gms. morpholine affords aninety percent yield (633 gms.) of nonylphenyltetramethylphosphorodiamidate: ##STR36##

EXAMPLE 6

In a one liter flask, equipped as in Example 4, are placedcyclohexanedimethanol 1,4 (3 moles), phosphorus oxychloride (3 moles)and pyridine (3 grams). The procedure of Example 4 is then followed andthe reaction mixture is diluted with chlorobenzene and added to 4 molesof dimethylamine in caustic. The product is cyclohexylenedimethylenebis(tetramethylphosphorodiamidate), [(H₃ C)₂ N]₂ (O)POCHl₂ C₆ H₁₀ CH₂OP(O)[N(CH₃)₂ ]₂.

Dimethylamine may be replaced by other secondary amines to afforddesired analogous phosphoroamidates.

EXAMPLE 7

To a 50 gal. steel-jacketed vessel, equipped with agitator andthermowell, there is charged phosphorus oxychloride and diethyleneglycol in a 2:1 molar ratio. After reaction at 15° C. for two hours and30° C. for one hour, there is added a 25 percent solution ofdimethylamine in caustic in a ratio of four moles of dimethylamine toeach mole of diethylene glycol bis phosphorodichloridate intermediate.The temperature is lowered to 15° C. and held for 30 minutes. An 88percent yield of product is afforded, which is diethylene glycolbis(tetramethylphosphorodiamidate), [(H₃ C)₂ N]₂ (O)POCH₂ CH₂ OCH₂ CH₂OP(O)[N(CH₃)₂ ]₂.

The compounds of the present invention are useful as flame retardantsfor a wide variety of natural and synthetic polymer materials. Thecompounds may be used in concentrations of from about 0.1 percent byweight of polymer up to about 50 weight percent or more depending on theparticular use for which the polymer material is intended.

Synthetic polymer materials, i.e., those high molecular weight organicmaterials which are not found in nature, with which the compounds of theinvention are advantageously employed may be either linear orcrosslinked polymers and may be in the form of sheets, coatings, foamsand the like. They may be either those which are produced by addition orcondensation polymerization.

An important class of polymers which are beneficially flame retardedwith the compounds of the invention are those obtained from apolymerizable monomer compound having ethylenic unsaturation. Aparticularly preferred class of polymers which are flame retardedconsist of the polymerized vinyl and vinylidene compounds, i.e., thosehaving the CH₂ ═ C < radical. Compounds having such a radical are, forexample, the solid polymeric alkenes, such as polyethylene,polypropylene, polyisobutylene or ethylene/propylene copolymers;polymerized acrylyl and alkacrylyl compounds such as acrylic,fluoroacrylic and methacrylic acids, anhydrides, esters, nitriles andamides, for example, acrylonitrile, ethyl or butyl acrylate, methyl orethyl methacrylate, methoxymethyl or 2-(2-butoxyethoxy)ethylmethacrylate, 2-(cyanoethoxy)ethyl 3-(3-cyanopropoxy)propyl acrylate ormethacrylate, 2(diethylamino)ethyl or 2-chloroethyl acrylate ormethacrylate, acrylic anhydride or methacrylic anhydride; methacrylamideor chloroacrylamide; ethyl or butyl chloroacrylate; the olefinicaldehydes such as acrolein, methacrolein and their acetals; the vinyland vinylidene halides such as vinyl chloride, vinyl fluoride,vinylidene fluoride and 1-chloro-1-fluoroethylene; polyvinyl alcohol;the vinyl carboxylates such as vinyl acetate, vinyl chloroacetate, vinylpropionate, and vinyl 2-ethyl-hexanoate; the N-vinyl imides such asN-vinyl phthalimide and N-vinylsuccinamide; the N-vinyl lactams such asN-vinyl caprolactam and N-vinyl butyrolactam; vinyl aromatic hydrocarboncompounds such as styrene, alpha-methylstyrene, 2,4-dichlorostyrene,alpha- or beta-vinylnaphthalene, divinyl benzene and vinyl fluorene; thevinyl ethers such as ethyl vinyl ether or isobutyl vinyl ether;vinyl-substituted heterocyclic compounds such as vinyl pyridine, vinylpyrrolidone, vinylfuran or vinylthiophene; the vinyl or vinylideneketones such as methyl vinyl ketone or isopropenyl ethyl ketone;vinylidene cyanide. Homopolymers of the above compounds or copolymersand terpolymers thereof are beneficially flame retarded by the compoundsof the present invention. Examples of such copolymers or terpolymers arethose obtained by polymerization of the following monomer mixtures;vinyl chloride/vinyl acetate, ethylene/vinyl chloride/vinyl acetate,acrylonitrile/vinyl pyridine, styrenemethyl/methacrylate,styrene/N-vinyl pyrrolidone, cyclohexyl methacrylate/vinylchloroacetate, acrylonitrile/vinylidene cyanide, methylmethacrylate/vinyl acetate, ethyl acrylate/methacrylamide/ethylchloroacrylate, vinyl chloride/vinylidene chloride/vinyl acetate.

Other polymers of compounds having the ethylenic group, >C ═ C<, arehomopolymers, copolymers and terpolymers of the alpha-, beta-olefinicdicarboxylic acids and derivatives thereof such as the anhydrides,esters, amides, nitriles and imides, for example, methyl, butyl,2-ethylhexyl or dodecyl fumarate or maleate; maleic, chloromaleic,citraconic or itaconic anhydride; fumaronitrile, dichlorofumaronitrileor citracononitrile; fumaramide, maleamide or N-phenyl maleamide.Examples of particularly useful polymers and terpolymers prepared fromthe alpha-, beta-olefinic dicarboxylic compounds are the copolymers ofmaleic anhydride and a vinyl compound such as ethylene, propylene,isobutylene, styrene, alpha methylstyrene, vinyl acetate, vinylpropionate, methyl isopropenyl ketone, isobutyl vinyl ether, thecopolymers of dialkyl fumarate such as ethyl or butyl fumarate and vinylcompounds such as styrene, vinyl acetate, vinylidene chloride, ethylmethacrylate, acrylonitrile and the like.

The compounds of the invention act as flame retardants for the polymersand copolymers of unsaturated, cyclic esters of carbonic acid, forexample, homopolymeric vinylene carbonate or the copolymers of vinylenecarbonate with ethylenic compounds such as ethylene, vinyl chloride,vinyl acetate, 1,3-butadiene, acrylonitrile, methacrylonitrile, or theesters of methacrylic or acrylic acid.

Readily flame retarded by the compounds of the invention are also thepolyarylcarbonate polymers such as the linear polyarylcarbonates formedfrom diphenols or dihydroxy aromatic compounds including single andfused-ring nucleii with two hydroxy groups as well asmonohydroxy-substituted aromatic residues joined in pairs by variousconnecting linkages. Examples of the foregoing include dihydroxybenzenes, naphthalenes and the like, the dihydroxydiphenyl ethers,sulfones, alkanes, ketones and the like.

The compounds of the invention also act as flame retardants forpolymers, copolymers or terpolymers of polymerizable compounds having aplurality of double bonds, for example, rubbery, conjugated dienepolymerizates such as homopolymerized 3-butadiene, 2-chlorobutadiene orisoprene and linear copolymers or terpolymers such asbutadiene/acrylonitrile, isobutylene/butadiene, butadiene/styrene;esters of saturated di- or poly-hydroxy compounds with olefiniccarboxylic acids such as ethylene glycol dimethacrylate, triethyleneglycol dicrotonate or glyceryl triacrylate; esters of olefinic alcoholswith dicarboxylic acids or with olefinic monocarboxylic acids such asdiallyl adipate, divinyl succinate, diallyl fumarate, allyl methacrylateor crotyl acrylate and other diethylenically unsaturated compounds suchas diallyl carbonate, divinyl ether or divinylbenzene, as well as thecrosslinked polymeric materials such as methyl methacrylate/diallylmethacrylate copolymer or butadiene/styrene/divinyl benzene terpolymer.

The cellulose derivatives are flame retarded by the compounds of thepresent invention. For example, cellulose esters such as celluloseacetate, cellulose triacetate or cellulose butyrate, the celluloseethers such as methyl or ethyl cellulose, cellulose nitrate,carboxymethyl cellulose, cellophane, rayon, regenerated rayon the thelike may be flame retarded.

The compounds of the present invention are well suited for flameretarding liquid resin compositions of the polyester type, for example,the linear polyesters which are obtained by the reaction of one or morepolyhydric alcohols with one or more alpha, beta-unsaturatedpolycarboxylic acids alone or in combination with one or more saturatedpolycarboxylic acid compounds, or the crosslinked polyester resins whichare obtained by reacting a linear polyester with a compound containing aCH₂ = C group.

The compounds of the present invention are compatible flame retardantsfor epoxy resins. Such resins are condensation products formed by thereaction of a polyhydroxy compound and epichlorohydrin, whichcondensation products are subsequently cured by the addition ofcrosslinking agents. The hydroxy compounds may be, for example, ethyleneglycol, 4,4'-isopropylidenediphenol and similar materials. Thecrosslinking agent employed in the curing step may be a dicarboxyliccompound such as phthalic anhydride or adipic acid, but is moregenerally a polyamine such as ethylene diamine, paraphenylamine diamineor diethylene triamine.

Polyurethanes are a class of polymer materials which are flame retardedby the compounds of the present invention. The polyurethanes, like theabove-mentioned polyesters, are materials which are employed instructural applications, for example, as insulating foams, in themanufacture of textile fibers, as resin bases in the manufacture ofcurable coating compositions and as impregnating adhesives in thefabrication of laminates of wood and other fibrous materials.Essentially, the polyurethanes are condensation products of adiisocyanate and a compound having a molecular weight of at least 500and preferably about 1500-5000 and at least two reactive hydrogen ions.The useful active-hydrogen containing compounds may be polyestersprepared from polycarboxylic acids and polyhydric alcohols, polyhydricpolyalkylene ethers having at least two hydroxy groups, polythioetherglycols, polyesteramides and similar materials.

The polyesters or polyester amides used for the production of thepolyurethane may be branched and/or linear, for example, the esters ofadipic, sebasic, 6-aminocaproic, phthalic, isophthalic, terephthalic,oxalic, malonic, succinic, maleic, cyclohexane-1,2-dicarboxylic,cyclohexane-1,4-dicarboxylic, polyacrylic, naphthalene-1,2-dicarboxylic,fumaric or itaconic acids with polyalcohols such as ethylene glycol,diethylene glycol, pentaglycol, glycerol, sorbitol, triethanolamineand/or amino alcohols such as ethanolamine, 3-aminopropanol, and withmixtures of the above polyalcohols and amines.

The alkylene glycols and polyoxyalkylene or polythioalkylene glycolsused in the production of polyurethanes may be ethylene glycol,propylene glycol, butylene glycol, diethylene glycol, triethyleneglycol, polythioethylene glycol, dipropylene glycol and the like.

Generally, any of the polyesters, polyisocyanate-modified polyesters,polyester amides, polyisocyanate-modified polyester-amides, alkyleneglycols, polyisocyanate-modified alkylene glycols, polyoxyalkyleneglycols and polyisocyanate-modified polyoxyalkylene glycols having threereactive hydrogen atoms, three reactive carboxylic and/or especiallyhydroxyl groups may be employed in the production of polyurethanes.Moreover, any organic compound containing at least two radicals selectedfrom the group consisting of hydroxy and carboxy groups may be employed.

The organic polyisocyanates useful for the production of polyurethanesinclude ethylene diisocyanate, ethylidene diisocyanate,propylene-1,2-diisocyanate, m-phenylene diisocyanate, 2,4-tolylenediisocyanate, triphenylmethane triisocyanate, or polyisocyanates inblocked or inactive form such as the bisphenyl carbamates of tolylenediisocyanate and the like.

Phenolic resins are flame retarded by the compounds of the presentinvention, which compounds may be incorporated into the phenolic resineither by milling and molding applications or by addition tofilm-forming or impregnating and bonding solutions prior to casting.Phenolic resins with which the present compounds are employed are, forexample, the phenol-aldehyde resins prepared from phenols such asphenol, cresol, xylinol, resorcinol, 4-butylphenol, cumylphenol,4-phenylphenol, nonylphenol, and aldehydes such as formaldehyde,acetaldehyde or butyraldehyde in the presence of either acetic or basiccatalysts, depending upon whether the resin is intended for use as amolding or extruding resin or as the resin base in coating andimpregnating compositions.

Aminoplasts are another group of aldehyde resins which are flameretarded by the compounds of the invention. Examples of aminoplasts arethe heat-convertible condensation products of an aldehyde with urea,thiourea, guanidine, cyanamide, dicyandiamide, alkyl or aryl guanaminesand the triazines such as melamine, 2-fluoro-4,6-diamino-1,3,5-triazineand the like. When the aminoplasts are to be used as impregnatingagents, bonding adhesives, coatings and in casting the films, thecompounds of the present invention are incorporated into solutions orsuspensions in which the aminoplast is carried. The resulting mixturesgive strong, fire-retardant laminates when sheets of paper, glass, clothor fabric are impregnated therewith and cured.

Another class of compounds which are flame retarded by the compounds ofthe present invention are the nylons, for example, the superpolyamideswhich are generally obtained by the condensation of a diamine, forexample, hexamethylene diamine with a dicarboxylic acid, for example,adipic acid.

Other polyamides which are flame retarded in accordance with the presentinvention are the polypeptides which may be prepared, for example, byreaction of N-carbobenzyl oxyglycine with glycine or mixture of glycineand lysine or an N-carboxy amino acid anhydride such asN-carboxy-DL-phenylalanine anhydride, piperidone,2-oxyhexamethyleneimine and other cyclic amides. The compounds of thepresent invention can be incorporated into molding or extrudingcompositions for a flame retardant effect.

The compounds of the present invention are also useful as flameretardants for linear polymers obtained by the self-condensation ofbifunctional compounds, for example, the polyethers which are derived bythe self-condensation of dihydric alcohols such as ethylene glycol,propylene glycol or hexamethylene glycol; the polyesters which areobtained by the self-condensation of hydroxy acids such as lactic acidor 4-hydroxybutyric acid; the polyamides which are prepared by theself-condensation of aminocarboxylic acids such as 4-aminobutyric acid;the polyanhydrides which are formed by the self-condensation ofdicarboxylic acids such as sebasic or adipic acid.

The preferred synthetic polymer materials which are flame retarded bythe compounds of the present invention are the vinyl halide polymers inthe form of milled products, plastisols and foams, rigid and flexiblepolyurethane coating and foams, epoxy resins, ABS and GRS rubbers,aminoplasts and phenolics. The vinyl halide polymers can be simple,mixed homopolymers of vinyl chloride or vinylidene chloride, such aspolyvinyl chloride or polyvinylidene chloride, or copolymers orterpolymers in which the essential polymeric structure of polyvinylchloride is interspersed at intervals with residues of otherethylenically unsaturated compounds copolymerizable therewith. Theessential properties of the polymeric structure of polyvinyl chloride isretained if not more than about 40 percent of a comonomer iscopolymerized therewith. Especially preferred copolymers includeethylene/vinyl chloride and vinyl chloride/acrylonitrile copolymers.Especially preferred terpolymers include ethylene/vinylchloride/acrylonitrile, ethylene/vinyl chloride/acrylic acid andethylene/vinyl chloride/acrylamide terpolymers.

Natural polymeric materials which may be flame retarded by the compoundsof the present invention include natural rubber, cellulose esters, forexample, cellulose acetate and cellulose nitrate, ethyl cellulose, corkand wood flour products and similar cellulosic materials.

The polymer formulations which are flame retarded in accordance with thepresent invention, whether in sheet or film form or of foam or moldedstructure, may contain various conventional additives such as fillers,extenders crosslinking agents and colorants. Minor amounts ofstabilizers, for example, are usually incorporated to reduce the effectsof heat and light.

When foamable compositions are used, the composition may be aself-blowing polymer or the polymer may be blown by chemical ormechanical means or by the use of compressed gas. Fillers which arefrequently employed to lower the cost of the finished material and tomodify its properies include calcium carbonate and magnesium silicate.When fillers are employed, they are generally present in an amount of upto about 150 parts by weight of filler per 100 parts by weight ofpolymer formulation.

Where a colored or tinted composition is desired, colorants orcolor-pigments are incorporated in amounts of from about one to aboutfive parts by weight to 100 parts by weight of polymer.

Surfactants such as silicones are normally added to foam formulationswhich are mechanically frothed. The surfactants reduced the surfacetension of the foam and thereby increase the air or gas entrapmentcharacteristics of the foam.

Additionally, glass-forming inorganic materials such as zinc borate,zinc oxide, lead oxide, lead silicate and silicon dioxide may be addedto decrease the flame and smoke generating characteristics of thepolymer. The flame retardant compounds of the present invention areextremely advantageous because of the following combination ofproperties: (1) The compounds are stable at temperatures somewhat inexcess of 350° C. and can therefore be processed on standard machinery,such as milling machines, without degradation or color loss. (2) Thecompounds contain little or no chlorine and therefore contribute littleor no hydrogen chloride gas during exposure to flames. (3) The compoundsare amenable to formulation with a less stable acid generator andtherefore can be made todegrade at lower temperatures if necessary. (4)The compounds are excellent acid scavengers, thereby decreasing theamount of acid radicals evolved by burning materials. (5) The compoundshave high solubility and compatibility with a wide variety of syntheticand natural polymer materials.

The following examples will serve to illustrate the utility of the flameretardant compounds of the present invention in various polymersubstances. The "oxygen index" referred to is that data obtained inaccordance with ASTM D2863-70 and is defined as the minimumconcentration of oxygen, expressed as volume percent, in a mixture ofoxygen and nitrogen that will just support combustion of the materialunder the conditions of the test procedure.

EXAMPLE 8

In this example, the compound of Example 2 is compared with acommercially available flame retardant (ethylene glycol polyphosphate)in a commercial epoxy resin ("EPI-REZ", a trade mark of CelaneseChemical Company for their epoxy resin). The comparative properties ofthe resin containing 5 and 10 phr (parts per hundred resin) of the flameretardants are shown in the table below.

                  TABLE I                                                         ______________________________________                                        Flame            Volatility                                                                              Tensile                                                                              Oxygen Index                                Retardant phr    % Loss    psi    % Oxygen                                    ______________________________________                                            ethylene   5     +0.59   2650   21.2                                          glycol                                                                        polyphos- 10     +0.03   1920   21.2                                          phate                                                                         Example 2 5      +0.01   3200   22.0                                          Compound                                                                      Example 2 10     +0.02   2880   24.0                                          Compound                                                                  ______________________________________                                    

EXAMPLE 9

In this example, the compound of Example 2 is formulated with apolymethyl methacrylate resin and compared with a control samplecontaining no flame retardant material. The control sample of polymethylmethacrylate had an oxygen index of 16.8 whereas the sample ofpolymethyl methacrylate containing 10 phr of the compound of Example 2of the present invention had an oxygen index of 18.4 and a polymethylmethacrylate sample containing 30 phr of the compound of Example 2 hadan oxygen index of 21.9.

EXAMPLE 10

The compound of Example 2 is compared with ethylene glycol polyphosphatein a melamine/formaldehyde resin at a level of 5 phr. The resincharacteristics are shown in the table below:

                  TABLE II                                                        ______________________________________                                                             Volatility Oxygen Index -                                Flame Retardant                                                                            phr     %Loss      %Oxygen                                       ______________________________________                                        Ethylene glycol                                                                            5       12.0       48.2                                          polyphosphate                                                                 Compound of  5       10         49.3                                          Example 2                                                                     ______________________________________                                    

EXAMPLE 11

The compound of Example 2 was formulated at 10 and 30 phr with athermoplastic polyurethane resin. The material was rolled-milled forfive minutes at 330° F., and molded at 320° F. for five minutes at 1000psi. The characteristics of the resin are set forth in the followingtable.

                  TABLE III                                                       ______________________________________                                                                  Oxygen Index                                        Flame Retardant phr       % Oxygen                                            ______________________________________                                        Control         --         20.6                                               Compound of                                                                   Example 2       10         22.4                                               Compound of                                                                   Example 2       30         27.6                                               ______________________________________                                    

Comparable flame retardancy is attained by substituting the compounds ofExamples 3, 4, 5, 6 and 7 for the compound of Example 2 in theformulations of Examples 7 through 11.

While the invention has been described hereinabove with regard tocertain illustrative, specific embodiments, it is not so limited sincemany modifications and variations are possible in the light of the aboveteachings. It is understood, therefore, that the invention may bepracticed otherwise than as specifically described without departingfrom the spirit and scope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A compound of theformula ##STR37## wherein R represents an alkylene group of 1 to 50carbon atoms or an arylene group;R₃ and R₄ individually represent analkyl group of 1 to 10 carbon atoms; X represents oxygen or sulfur; Zrepresents the residue of a hydroxyl-containing moiety which will reactwith a phosphorus oxyhalide or phosphorus thiohalide, said residuecontaining no free hydroxyl groups; and n represents an integer of from1 to
 40. 2. Compound of claim 1 wherein R represents an alkylene groupof 1 to 10 carbon atoms, R₃ and R₄ represent methyl and X representsoxygen.